for National Geographic News
This is the second of a three-part series on how scientists are turning to nature to develop powerful new military technologiesthe subject of a new National Geographic EXPLORER documentary, Secret Weapons, premiering in the United States on MSNBC on Sunday, March 16, 8 p.m. ET/PT.
Black flies, wasps, and bumblebees may be the bane of backyard barbeques, but their keen ability to navigate from potato chip to hamburger to bare arm is the inspiration for a host of robots that may soon be hailed as international heroes.
Scientists from around the world are reverse-engineering the mechanics of insects as they design midget robots to scout battlefields, search for victims trapped in rubble, and record images as they hover over distant planets.
"Insect flight has many, many desirable features that, if we are able to mimic, we will be able to improve the performance of vehicles," said Kakkattukuzhy Isaac, a professor of aerospace engineering at the University of Missouri-Rolla.
These features include the ability to zero in and land precisely on a potato chip and then flap their wings to buzz off with blazing speed. While annoying to the person about to munch the chip, such insect maneuverability awes scientists.
Isaac and other researchers believe that robots inspired by the natural ability of insects will help them overcome several of the problems that hamper progress using traditional engineering methods.
"Some of nature's solutions are surprisingly simple and effective, and are not always dreamt up by engineering-style thinking," said Mandyam Srinivasan, a biologist at the Australian National University in Canberra.
Bug Vision and Flight
Srinivasan and his colleagues have spent the last 15 years sorting out how insects such as bees see with the acuity to allow perfect landings on the edge of a potato chip, despite the fact that the closeness of their eyes prevents them from seeing stereo imagery like humans.
To accomplish this, the insects use cues based on image motion to gauge the distances to objects. Srinivasan likens it to driving a car down a country highway. The trees at the side of the road whiz by, whereas the mountains on the distant horizon hardly move. The closer an object is to the observer, the faster it appears to move.
"The brains of insects measure the pattern of image motion and use it to perceive the world in 3-D to avoid collisions with obstacles and to perform smooth landings," said Srinivasan.
Since this method of vision is much simpler than processing images in stereo to see in three dimensions, it requires much less brain power, or in the case of robotics, a much smaller and relatively inexpensive computer. "Thus it allows us to devise autonomously navigating robots that are cheaper, simpler, smaller," said Srinivasan.
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